Movie Theater Effect

I'm currently shooting a short film and am completely new to After Effects. I have a scene that takes place in a movie theater, while a film is being screened. No film will really be screened during the shooting, and I would like to create some artificial flashes of light on the seats from the screen, in order to simulate this.
My shot is something like this photo here: http://www.fastcodesign.com/multisite_files/codesign/imagecache/960/article...

Does anyone know a tutorial that can help with this, or can give some basic instructions on this for a total newbie?

Here's one recipe(this effect could be accomplished a lot of different ways, put add adjustment layer over you footage and add a levels effect that simulates the brightness of the screen. Change the adjustment layers transfer mode(I used Luminosity). Lastly add a wiggle effect to the adjustment layers opacity.

wiggle(4,45)

I used your picture and before I started I really brought down the initial brightness using a curves effect. Here's a quick example project to look at, if it helps: 5131_theatrecs5.5.aep.zip

Johnny Cuevas, Editor
Thinkck.com

"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.

"I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work."
---THOMAS EDISON on inventing the light bulb.